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      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <fcntl.h>
     18 #include <errno.h>
     19 #include <math.h>
     20 #include <poll.h>
     21 #include <unistd.h>
     22 #include <dirent.h>
     23 #include <sys/select.h>
     24 
     25 #include <linux/max9635.h>
     26 
     27 #include <cutils/log.h>
     28 
     29 #include "LightSensor.h"
     30 
     31 /*****************************************************************************/
     32 
     33 LightSensor::LightSensor()
     34     : SensorBase(LIGHTING_DEVICE_NAME, "max9635_als"),
     35       mEnabled(0),
     36       mInputReader(4),
     37       mHasPendingEvent(false)
     38 {
     39     mPendingEvent.version = sizeof(sensors_event_t);
     40     mPendingEvent.sensor = ID_L;
     41     mPendingEvent.type = SENSOR_TYPE_LIGHT;
     42     memset(mPendingEvent.data, 0, sizeof(mPendingEvent.data));
     43 }
     44 
     45 LightSensor::~LightSensor() {
     46 }
     47 
     48 int LightSensor::enable(int32_t, int en) {
     49     int err;
     50     en = en ? 1 : 0;
     51     if(mEnabled != en) {
     52         if (en) {
     53             open_device();
     54         }
     55         err = ioctl(dev_fd, MAX9635_IOCTL_SET_ENABLE,&en);
     56         err = err<0 ? -errno : 0;
     57         LOGE_IF(err, "MAX9635_IOCTL_SET_ENABLE failed (%s)", strerror(-err));
     58         if (!err) {
     59             mEnabled = en;
     60         }
     61         if (!en) {
     62             close_device();
     63         }
     64     }
     65     return 0;
     66 }
     67 
     68 bool LightSensor::hasPendingEvents() const {
     69     return mHasPendingEvent;
     70 }
     71 
     72 int LightSensor::readEvents(sensors_event_t* data, int count)
     73 {
     74     if (count < 1)
     75         return -EINVAL;
     76 
     77     if (mHasPendingEvent) {
     78         mHasPendingEvent = false;
     79         mPendingEvent.timestamp = getTimestamp();
     80         *data = mPendingEvent;
     81         return mEnabled ? 1 : 0;
     82     }
     83 
     84     ssize_t n = mInputReader.fill(data_fd);
     85     if (n < 0)
     86         return n;
     87 
     88     int numEventReceived = 0;
     89     input_event const* event;
     90 
     91     while (count && mInputReader.readEvent(&event)) {
     92         int type = event->type;
     93         if (type == EV_MSC) {
     94             if (event->code == EVENT_TYPE_LIGHT) {
     95                 mPendingEvent.light = indexToValue(event->value);
     96             }
     97         } else if (type == EV_SYN) {
     98             mPendingEvent.timestamp = timevalToNano(event->time);
     99             if (mEnabled) {
    100                 *data++ = mPendingEvent;
    101                 count--;
    102                 numEventReceived++;
    103             }
    104         } else {
    105             if (type == 4 && event->code == 3) {
    106                 // weird, not sure why we're getting this all the time
    107             } else {
    108                 LOGE("LightSensor: unknown event (type=%d, code=%d)",
    109                         type, event->code);
    110             }
    111         }
    112         mInputReader.next();
    113     }
    114 
    115     return numEventReceived;
    116 }
    117 
    118 float LightSensor::indexToValue(size_t index) const
    119 {
    120     return float(index);
    121 }
    122